Well, I don't have a "good" answer, but I will share my experience so far.
Back when I first purchased AD Expert, I played with Algor design check a little and it seemed pretty nice for a marketing add-on.
Well, MS operating systems being what they are, I had to format my system within a month or two and ever since I have NOT been able to use Algor.
I have asked tech support at Alibre about it, and they kindly directed me to autodesk/algor to request help with the license. However I have tried several times since 2007 (it is now 2010) and have yet to receive a response from them.
So, unless somebody can shed some light on the subject, I would have to say that we only get ONE install, so guard it well
PS. I'd very much like to regain the use of Algor design check.